1. Field of the Invention
The present invention relates to a support apparatus for supporting a syphon.
More specifically, the present invention relates to a support apparatus and method for supporting a stationary syphon within a rotating cylinder.
2. Background Information
The present invention provides a method and apparatus for heating a roll, the apparatus using a stationary syphon fluid passage which extends from the inside surface of a rotating cylinder roll to a rotary joint connected to external stationary piping. The invention more specifically provides for a rotating internal support for the stationary syphon, the support being adjustable so as to position and hold the stationary syphon on the rotational axis of the rotating cylinder roll, so that the stationary internal flow passage of the stationary syphon can remove condensed steam, heat transfer fluid or cooling water from the inside surface of the rotating cylinder. The rotating syphon support is mounted to the inside surface of the rotating cylinder and it supports the syphon pipe through renewable bushings.
The rotating cylinder is used to dry paper, foodstuffs, textiles, and the like, as they pass over the outside surface of the rotating cylinder. Alternatively, the rotating cylinder is used to heat or cool similar products as they pass over the outside surface of the rotating cylinder.
Conventional stationary syphons are either cantilevered from the external rotary joint or supported by brackets that are either bolted to the dryer journal or to the inside surface of the dryer head. These prior art arrangements require the dryer journal to have a large diameter bore or the dryer head to have a machined surface on the inside for bolting the bracket to the head.
However, many older dryers have small journal bores and no inside cylinder head machining. This situation often prevents such dryers from being upgraded to stationary syphons. In the present invention, the stationary syphon pipe can be supported inside the dryer by a carbon graphite bushing that is mounted on a bracket that is, in turn, supported through a tripod mounting to the inside dryer surface. The arrangement according to the present invention allows upgrading dryers to stationary syphons for increased production at a lower cost than replacing the dryer so that traditional stationary syphons are able to be used.
Wet paper webs are dried by a series of metal rolls in the paper making process. These rolls are heated by steam that passes through a rotary joint, through the roll journal, and into the inside of the metal roll. The steam is supplied to the rotary joint from piping that is fixed or stationary. The steam then goes through the journal of the roll. Once inside the roll, the steam condenses as the heat from the steam is transferred to the inside surface of the roll. The condensed steam, which is water or “condensate” must then be removed so that the roll does not fill up with water. The water is removed through a pipe called a “syphon”. The condensate flows into the syphon pipe, up to the enter axis of the roll and then out the roll through the syphon pipe that extends through the roll journal. Syphons either turn with the roll (“rotary” syphons) or remain fixed with the joint (“stationary” syphons).
Stationary syphons that are used to remove condensate are attached to a stationary portion of the rotary joint in order to prevent rotation of the syphon and to seal the inlet flow of steam from the outlet flow of condensate and blow through steam. Conventional stationary syphons are mounted in one of three ways. The most popular method is to use a large cantilevered support tube mounted in the rotary joint. The tube extends through the dryer journal and into the dryer roll. The cantilever tube supports the syphon pipe that extends from the dryer axis to the dryer shell. The tube is generally stiffer and stronger than standard pipe to support the weight and other forces.
The second method of supporting the stationary syphon is to use a large cantilevered support tube that is mounted to the outside end of the journal. The rotary joint can be mounted either to the end of the dryer journal or to an external support. In this configuration, the condensate pipe is attached to a stationary portion of the rotary joint and extends through the support tube to the inside of the dryer cylinder. The tube supports the stationary syphon pipe on the inboard end of the support tube, inside the cylinder. The support tube is larger in diameter, stiffer, and stronger than the condensate pipe and is therefore capable of supporting the syphon weight and associated loading.
The third method of supporting the stationary syphon is a bracket support that is mounted inside the roll where the journal bore terminates inside the roll. The rotary joint can be mounted either to the end of the dryer journal or to an external support. In this configuration, the condensate pipe is attached to a stationary portion of the rotary joint and extends through the journal to the inside of the dryer cylinder. The bracket supports the condensate pipe at the end that is located inside the dryer. The bracket is mounted close to the inboard end of the pipe to give it proper support. The bracket spins with the roll while the condensate pipe remains stationary (that is, not rotating). Carbon graphite or equivalent bushings are used in the bracket to allow relative motion between the bracket and the condensate pipe. The bracket is stiffer and stronger than the condensate pipe and carries the weight and forces on the stationary syphon pipe.
The aforementioned prior art arrangements are limited to rolls that have internal machining or large journal bores. New paper machines are often designed for stationary syphon systems. Older machines, however, were often designed for rotary syphons that mounted to the inside surface of the roll shell and could be used with small journal bores. Consequently, older machines often have small journal bores without internal machining to allow the use of an internal support bracket.
Advances in syphon design and machine speed make stationary syphons the preferred equipment on many older machines. Stationary syphons cannot be used, however, because of the problems that arise in installing them in these older paper machine dryers.
To make it possible to mount stationary syphons in older paper machine rolls, the method and apparatus of the present invention can be used to support a stationary syphon pipe inside the dryer cylinder without the need for internal machining of the dryer head or large diameter journal bores. In the mounting arrangements of the present invention, the support is provided through a bushing that is held on the centerline of the roll axis and supported by a bracket and tripod system that extends outwardly to the inside surface of the dryer roll. The bushing allows the bracket to rotate relative to the stationary syphon pipe. This support system further includes the ability to locate the bushing along the roll journal axis, even if the inside roll surface is not concentric with the journal bore, as may be the case in older machine rolls.
In the concept of the present invention, the bushings for the condensate pipe are mounted in a center hub. The hub is supported by three length adjustable legs, arms or spoke assemblies. At the end of each spoke assembly is a plate or foot that contacts the inside or internal surface of the roll shell. In a preferred embodiment of the present invention, two of the spoke assemblies are rigid after adjustments are made. The end of the third spoke assembly is able to move along the spoke axis while staying in contact with both the hub and the shell of the dryer. The ability to move is necessary to apply and maintain a force to the shell, in order to provide a robust mounting. The force is generated by a spring mounted on the third spoke. This spring keeps the support assembly in place during operation.
The concept of the present invention is different from the prior art because it enables the mounting and centering of the stationary syphon in any roll regardless of the date of construction of such dryer roll. The concept is an improvement over the prior art arrangements because it serves a segment of the commercial market that the prior art designs cannot.
The arrangement according to the present invention would have particular application to dryers having an inside diameter of between 44.8″ to 46.8″. However, the present invention is not limited in any way to dryers having the aforementioned diameters.
Therefore, the primary feature of the present invention is the provision of a support apparatus for supporting a syphon within a rotating cylinder that overcomes the problems associated with the prior art machines and which makes a significant contribution to the papermaking art.
Another feature of the present invention is the provision of a support apparatus for supporting a syphon within a rotating cylinder that permits a retrofit to any type of drying, heating or cooling cylinder.
Other features and advantages of the present invention will be readily apparent to those skilled in the art by a consideration of the detailed description of a preferred embodiment of the present invention contained herein.